Method of making antifouling coatings.



Patented October 13, 1903. A

GEORGE D. COLEMAN, OF BOSTON, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO COLEMAN SHIP COPPERING COMPANY, A CORPORA- TION OF MAINE.

METHOD OF MAKING ANTIFOULING COATINGS.

SPECIFICATION forming part of Letters IE'atent No. 741,227, dated October 13, 1903.

Application, filed January 31, 1902. Serial No. 92,064. (No specimens.)

To all whom, it may concern:

Be it known that I, GEORGE D. COLEMAN, a citizen of the United States, residing at Boston, in the county of Suffolk and State of 5 Massachusetts, have invented certain new and useful Improvements in Methods of Making Antifouling Coatings; andI do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to an improved method of making an antifouling coating for ships bottoms or structures submerged in or exposed to the action of water,

and particularly sea-water.

The object of my invention is to produce an efficient method of making such antifouling coating; and to the above end it consists in the method hereinafter described, and particularly defined in the claims.

According to my invention I first apply to the structure a layer of paint, which will be proportionate in thickness to the thickness of the coating desired. The paint should preferably be a quick-drying paint, and for this purpose I prefer to employ a paint made of cement or paint substance mixed with varnish. The preferred'cement or paint sub- 0 stance consists of ordinary red lead or litharge of commerce mixed with raw linseed-oil to the consistency of putty, baked at a low temperature of 130 Fahrenheit and then. pulverized in a dry mill. The varnish is preferably made of forty gallons of linseed-oil mixed with one hundred pounds of Zanzibar or kauri gums. The mixture of this paint substance with this varnish produces the paint which I prefer for the body of my antio fouling coating. The consistency of this paint is preferably such that it can be laid upon the surface to be coated with a brush, although this is immaterial to my invention, as it may be laid on with any suitable means.

I then apply in any suitable manner, as by a blower, finely-divided metallic copper, preferably such as will be secured by sifting through an eighty-mesh sieve. The particles of comminuted copper will adhere to the tacky surface of paint, covering it with a impervious to water.

layer of particles of copper. The next step consists in rubbing, or burnishin g, or hammering the copper to embed or envelop the particles of copper in the layer of paint. This step results in embedding the particles of copper in and enveloping them by the paint, which is thereby brought to the surface through the interstices therebetween. .It is desirable in the manufacture of antifouling coatings to have the surface of the coating present a clean surface of substantially continuous copper, and to this end I next apply, preferably bymeans of a blower, to the coat- 'ing while the paint is still moist or tacky still more finelydivided metallic copper, preferably such as would be gotten by sifting through a one hundred and twentymesh sieve. The particles of copper adhere to the surface of the paint brought up by the rubbing or burnishing or hammering of the first layer of copper into the paint, and the entire exposed surface is covered with fine particles of copper. This surface is now rubbed or burnished or hammered, and the particles of the more finely divided copper fill the interstices between the larger particles of copper and take up the surplus paint, so that the entire surface of the coating is covered with particles of finely-divided metallic copper.

The preferred form of my invention, in So which I use the peculiar paint herein de scribed, is superior to that in which ordinary red lead is used, because this paint has high adhesive qualities, is tough, durable, and

This paint itself con tains the necessary ingredients to secure its rapid drying. So, while in its broader aspects my invention is not limited to any form of paint which may be employed for this purpose, in its narrower aspects this paint is 0 necessary to carrying out my process, and the claims are to be understood and read with this explanation.

WVhere the term red lead has been used I in the claims it is not to be understood as 5 limiting the invention thereto, since equivalent substances, such as litharge, may be sub ,stituted for red lead without departure from the invention.

Having thus described my invention, I

. claim as new and desire to secure by Letters Patent of the United States 1.- The method of making antifouling coatings for ships bottoms or structures submerged in or exposed to the action of water, and particularly sea-Water, which consists in applying to the surface to be coated a layer of quick-drying paint, in projecting particles of finely-divided metallic copper into the surface of this layer of paint while it is still moist, in rubbing or-hammering or burnishing the coating to force the particles of copper into the paint to embed them in and envelop them by the paint, in applying still more finely di- Vided metallic copper to the paint which comes to the surface between the particles of copper first applied and in rubbing or hammering or burnishing the coating to present a smooth surface closely studded with particles of bare metallic copper, substantially as described.

2. The method of making antifouling coatin g for ships bottoms or structures submerged in or exposed to the action of water and particularly sea-water, which consists in applying to the surface to be coated a layer of paint composed of a mixture with cement or paint substance formed of red lead and linseed-oil intimately united by baking, of a Varnish, in applying to this layer of paint while still moist, finely-divided metallic copper, in rubbing or hammering or burnishing the surface of the coating to embed the particles of co'p per in and envelop them by the paint, and to bring the paint to the surface around the particles of copper, in applying still more finely divided metallic copper to the paint so brought to the surface, and in rubbing or hammering or burnishing the surface of the coating to present a smooth surface closely studded with bare particles of finely-divided copper, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE D. COLEMAN. Witnesses:

HORACE VAN EVEREN, BENJAMIN PHILLIPS. 

